Influence of Stalk Residue Retention and Fertilization on the Rhizospheric Effect with Drip‐Irrigated Cotton

Abstract

Core Ideas Stalk residue retention and fertilizer increased organic carbon, total nitrogen, and microbial biomass carbon. Nitrogen‐phosphorus‐potassium plus poultry manure had the highest NO3–‐N and available nitrogen contents. Stalk residue retention plus fertilization had positive rhizospheric effect on soil organic carbon and NO3–‐N. Stalk residue retention plus fertilization had negative rhizospheric effect on total nitrogen and NH4+‐N. Stalk residue retention plus fertilization had no net rhizospheric effect on pH and microbial biomass carbon. ABSTRACTBy using less chemical fertilizer to produce cotton (Gossypium hirsutum L.), farmers could reduce input costs, increase efficiency, and protect the environment. The objective of this study was to determine the effects of stalk residue management and fertilizer application on the rhizospheric and bulk soil properties. The split‐plot design included two main plot treatments (stalk residue removal and stalk residue retention) and four subplot fertilizer treatments (no fertilizer; N, P, and K fertilizer; poultry manure; and NPK plus poultry manure). Results showed that stalk residue retention increased soil pH, whereas fertilization reduced it. Stalk residue retention and fertilizer application both increased organic C, total N, and microbial biomass C. The NPK plus poultry manure treatment had the highest nitrate (NO3–‐N) and available N contents. Stalk residue retention had negative rhizospheric effect on soil pH, total N, and ammonium (NH4+‐N) but positive rhizospheric effect on soil organic C, microbial biomass C, and NO3–‐N. The NPK plus poultry manure treatment had positive rhizospheric effect on soil pH, organic C, and NO3–‐N but negative rhizospheric effect on total soil N, microbial biomass C and NH4+‐N. Overall, stalk residue retention plus fertilization had positive rhizospheric effect on soil organic C and NO3–‐N, negative rhizospheric effect on total N and NH4+‐N, and no net rhizospheric effect on soil pH and microbial biomass C. Stalk residue retention improved soil quality and increased soil organic C and available N. Stalk residue retention plus NPK fertilizer and poultry manure can significantly increase soil organic C and active C components, thus ensuring high productivity.